U.S. patent application number 15/466962 was filed with the patent office on 2017-11-02 for side inject nozzle design for processing chamber.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Martin John RIPLEY, Agus Sofian TJANDRA.
Application Number | 20170314126 15/466962 |
Document ID | / |
Family ID | 60158821 |
Filed Date | 2017-11-02 |
United States Patent
Application |
20170314126 |
Kind Code |
A1 |
TJANDRA; Agus Sofian ; et
al. |
November 2, 2017 |
SIDE INJECT NOZZLE DESIGN FOR PROCESSING CHAMBER
Abstract
Implementations of the present disclosure provide apparatus and
method for improving gas distribution during thermal processing.
One implementation of the present disclosure provides an apparatus
for processing a substrate comprising a chamber body defining a
processing volume, a substrate support disposed in the processing
volume, wherein the substrate support has a substrate supporting
surface, a gas source assembly coupled to an inlet of the chamber
body, an exhaust assembly coupled to an outlet of the chamber body,
and a side gas assembly coupled to a sidewall of the chamber body,
wherein the side gas assembly comprises a gas inlet pointed in a
direction that is tangential to the edge of the substrate
supporting surface, and wherein the gas inlet, the inlet of the
chamber body, and the outlet of the chamber body are angularly
offset at about 90.degree. with respect to each other, and the gas
inlet, the inlet of the chamber body, and the outlet of the chamber
body are intersected by a common plane.
Inventors: |
TJANDRA; Agus Sofian; (San
Jose, CA) ; RIPLEY; Martin John; (San Jose,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
60158821 |
Appl. No.: |
15/466962 |
Filed: |
March 23, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62328669 |
Apr 28, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/67115 20130101;
C23C 16/4584 20130101; C23C 16/45563 20130101; C23C 16/46 20130101;
C23C 16/45502 20130101 |
International
Class: |
C23C 16/458 20060101
C23C016/458; C23C 16/46 20060101 C23C016/46; C23C 16/455 20060101
C23C016/455 |
Claims
1. An apparatus for processing a substrate, comprising: a chamber
body defining a processing volume; a substrate support disposed in
the processing volume, wherein the substrate support has a
substrate supporting surface; a gas source assembly in fluid
communication with an inlet of the chamber body; an exhaust
assembly in fluid communication with an outlet of the chamber body;
and a side gas assembly coupled to a sidewall of the chamber body,
wherein the side gas assembly comprises a gas inlet pointed in a
direction that is tangential to the edge of the substrate
supporting surface, and wherein the gas inlet, the inlet of the
chamber body, and the outlet of the chamber body are angularly
offset at about 90.degree. with respect to each other, and the gas
inlet, the inlet of the chamber body, and the outlet of the chamber
body are intersected by a common plane.
2. The apparatus of claim 1, wherein the gas source assembly is in
fluid communication with a first gas source.
3. The apparatus of claim 2, wherein the gas source assembly is
further in fluid communication with a second gas source, wherein
the first gas source and the second gas source are different in
chemical composition.
4. The apparatus of claim 2, wherein the side gas assembly is in
fluid communication with a third gas source that is different from
the first gas source in chemical composition, and the gas inlet of
the side gas assembly is pointed in a direction towards an edge of
the substrate supporting surface.
5. The apparatus of claim 4, wherein the first gas source comprises
an oxygen containing gas, and each of the second and third gas
sources comprises a hydrogen containing gas.
6. The apparatus of claim 1, wherein the side gas assembly is in
fluid communication with a third gas source, the third gas source
comprises an oxygen containing gas or a gas mixture of a hydrogen
containing gas and an oxygen containing gas, and the gas inlet of
the side gas assembly is pointed in a direction towards an edge of
the substrate supporting surface.
7. The apparatus of claim 1, wherein the side gas assembly provides
a gas flow along a flow path that is at a distance of about 5 mm to
about 10 mm from a tangent line of the substrate supporting surface
parallel to the flow path.
8. The apparatus of claim 1, wherein the gas inlet assembly and the
exhaust assembly are disposed on opposite sides of the chamber
body, and both the inlet and outlet of the chamber body have a
linear or azimuthal width approximately equals to a diameter of the
substrate support.
9. An apparatus for thermal processing a substrate, comprising: a
base ring having sidewalls defining a processing volume, wherein
the base ring has an inlet and an outlet formed through the
sidewalls, the inlet and the outlet are formed on opposite sides of
the base ring; a substrate support disposed in the processing
volume, wherein the substrate support has a substrate supporting
surface; a heat source positioned to provide thermal energy to the
processing volume; an exhaust assembly coupled to the outlet of the
base ring; and a side gas assembly coupled to a side port of the
base ring, wherein the side gas assembly comprises a gas inlet
pointing to a tangent of the substrate supporting surface, and the
side port, the inlet, and the outlet of the base ring are
substantially disposed at the same elevation.
10. The apparatus of claim 9, wherein the gas inlet is an elongated
channel extended along a direction towards the outlet.
11. The apparatus of claim 9, wherein the gas inlet is a
funnel-shaped structure that spreads out towards the processing
volume.
12. The apparatus of claim 9, further comprising: an injection
cartridge coupled to the base ring in the inlet, wherein the
injection cartridge is in fluid communication with a first gas
source comprising an oxygen containing gas and a hydrogen
containing gas.
13. The apparatus of claim 12, wherein the side gas assembly is in
fluid communication with a second gas source comprising hydrogen
radicals.
14. The apparatus of claim 9, wherein the gas inlet of the side gas
assembly is pointed in a direction that is tangential to the edge
of the substrate supporting surface.
15. The apparatus of claim 9, wherein the side port, the inlet, and
the outlet of the base ring are angularly offset at about
90.degree. with respect to each other.
16. A method for processing a substrate, comprising: positioning a
substrate in a processing volume of a process chamber, wherein the
process chamber has an inlet and an outlet formed on opposite sides
of the process chamber; providing a first gas flow from the inlet
to the outlet; pumping the processing volume using an exhaust
assembly coupled to the outlet; and providing a second gas flow
from a side port of the process chamber in a direction that is
tangential to an edge of the substrate so that the majority of the
second gas flows along a flow path towards the outlet.
17. The method of claim 16, further comprising: rotating the
substrate continuously about a center of the substrate.
18. The method of claim 17, wherein rotating the substrate
comprises rotating the substrate along a direction so that a
velocity of the second gas flow at an edge of the substrate is
slowed down by a factor of 5 or greater.
19. The method of claim 16, wherein the first gas flow comprises an
oxygen containing gas and a hydrogen containing gas, and the second
gas flow comprises hydrogen radicals.
20. The method of claim 16, further comprising heating the
substrate using a heat source disposed above or below the
processing volume.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent
application Ser. No. 62/328,669, filed Apr. 28, 2016, which is
herein incorporated by reference.
BACKGROUND
Field
[0002] The present disclosure relates generally to a semiconductor
processing tool and, more specifically, to a reactor with improved
gas flow distribution.
Description of the Related Art
[0003] Semiconductor substrates are processed for a wide variety of
applications, including the fabrication of integrated devices and
microdevices. One method of processing substrates includes growing
an oxide layer on an upper surface of the substrate within a
processing chamber. The oxide layer may be deposited by exposing
the substrate to oxygen and hydrogen gases while heating the
substrate with a radiant heat source. The oxygen radicals strike
the surface of the substrate to form a layer, for example a silicon
dioxide layer, on a silicon substrate.
[0004] Current processing chamber used for radical oxygen growth
have limited growth control, resulting in poor processing
uniformity. For example, low processing chamber pressure
requirements for radial oxygen growth and current gas inlet designs
result in gas reaching the substrate at a high velocity. The high
velocity of the gas causes impingement on the substrate and
prevents the gas from being adequately heated at the edge of the
substrate. On the other hand, oxygen radicals generated from
combustion quickly recombine to create a short life cycle for the
oxygen radicals. Therefore, the limited growth control due to the
high velocity of the gas combined with the short life cycle of
oxygen radicals results in greater growth at the center of the
substrate, and poor growth at the edges of the substrate.
[0005] Therefore, there is a need for an improved gas flow
distribution that provides growth control for more uniform film
growth throughout the substrate, i.e., from the center to the
edge.
SUMMARY
[0006] Implementations of the present disclosure provide apparatus
and method for improving gas distribution during thermal
processing. One implementation of the present disclosure provides
an apparatus for processing a substrate comprising a chamber body
defining a processing volume, a substrate support disposed in the
processing volume, wherein the substrate support has a substrate
supporting surface, a gas source assembly coupled to an inlet of
the chamber body, an exhaust assembly coupled to an outlet of the
chamber body, and a side gas assembly coupled to a sidewall of the
chamber body, wherein the side gas assembly comprises a gas inlet
pointed in a direction that is tangential to the edge of the
substrate supporting surface, and wherein the gas inlet, the inlet
of the chamber body, and the outlet of the chamber body are
angularly offset at about 90.degree. with respect to each other,
and the gas inlet, the inlet of the chamber body, and the outlet of
the chamber body are intersected by a common plane.
[0007] Another implementation of the present disclosure provides an
apparatus for processing a substrate comprising a base ring having
sidewalls defining a processing volume, wherein the base ring has
an inlet and an outlet formed through the sidewalls, the inlet and
the outlet are formed on opposite sides of the base ring, a
substrate support disposed in the processing volume, wherein the
substrate support has a substrate supporting surface, a heat source
positioned to provide thermal energy to the processing volume, an
exhaust assembly coupled to the outlet of the base ring, and a side
gas assembly coupled to a side port of the base ring, wherein the
side gas assembly comprises a gas inlet pointing to a tangent of
the substrate supporting surface, and the side port, the inlet, and
the outlet of the base ring are substantially disposed at the same
elevation.
[0008] Yet another implementation of the present disclosure
provides a method for processing a substrate comprising providing a
process chamber defining a processing volume, wherein the process
chamber has an inlet port and an exhaust port formed on opposite
sides of the process chamber, positioning a substrate in the
processing volume, providing a first gas flow from the inlet port
to the outlet port, pumping the processing volume using an exhaust
assembly coupled to the outlet port, and providing a second gas
flow from a side port of the process chamber in a direction that is
tangential to an edge of the substrate so that the majority of the
second gas flows along a flow path towards the outlet.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] So that the manner in which the above recited features of
the present disclosure can be understood in detail, a more
particular description of the disclosure, briefly summarized above,
may be had by reference to implementations, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical implementations
of this disclosure and are therefore not to be considered limiting
of its scope, for the disclosure may admit to other equally
effective implementations.
[0010] FIG. 1A is a schematic, cross-sectional representation of a
thermal processing chamber that may be used to practice
implementations of the present disclosure.
[0011] FIG. 1B is a schematic cross-sectional top view of the
thermal processing chamber according to one implementation of the
present disclosure.
[0012] FIG. 2A is a schematic cross-sectional top view of a side
injection assembly having an angled gas pipe according to one
implementation of the present disclosure.
[0013] FIG. 2B a schematic cross-sectional top view of a side
injection assembly having an angled gas pipe according to another
implementation of the present disclosure.
[0014] FIG. 3 is a schematic cross-sectional top view of a side
injection assembly having a split-type gas pipe according to one
implementation of the present disclosure.
[0015] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements
disclosed in one implementation may be beneficially utilized on
other implementations without specific recitation.
DETAILED DESCRIPTION
[0016] FIG. 1A is a schematic, cross-sectional representation of a
thermal processing chamber 100 that may be used to practice
implementations of the present disclosure. The thermal processing
chamber 100 generally includes a lamp assembly 110, a chamber
assembly 130 defining a processing volume 139, and a substrate
support 138 disposed in the processing volume 139. The processing
unit 124 is capable of providing a controlled thermal cycle that
heats a substrate 104 for processes such as, for example, thermal
annealing, thermal cleaning, thermal chemical vapor deposition,
thermal oxidation and thermal nitridation, etc
[0017] The lamp assembly 110 may be positioned relatively above the
substrate support 138 to supply heat to the processing volume 139
via a quartz window 114. The quartz window 114 is disposed between
the substrate 104 and the lamp assembly 110. The lamp assembly 110
may additionally or alternatively be disposed relatively below the
substrate support 138 in some implementations. It is noted that the
term "above" or "below" as used in this disclosure are not
referring to absolute directions. The lamp assembly 110 is
configured to house a heating source 108, such as a plurality of
tungsten-halogen lamps for providing a tailored infrared heating
means to a substrate 101 disposed on the substrate support 138. The
plurality of tungsten-halogen lamps may be disposed in a hexagonal
arrangement. The heating source 108 may be connected to a
controller 107 which may control the energy level of the heating
source 108 to achieve a uniform or tailored heating profile to the
substrate 101. In one example, the heating source 108 is capable of
rapidly heating the substrate 101 at a rate of from about
50.degree. C./s to about 280.degree. C./s.
[0018] The substrate 101 may be heated to a temperature ranging
from about 550 degrees Celsius to about less than 700 degrees
Celsius. The heating source 108 may provide zoned heating
(temperature tuning) of the substrate 101. Temperature tuning may
be performed to change the temperature of the substrate 101 at
certain locations while not affecting the rest of the substrate
temperature. In one implementation, the center of the substrate 101
is heated to a temperature that is 10 degrees Celsius to about 50
degrees Celsius higher than the temperature of the edge of the
substrate 101.
[0019] A silt valve 137 may be disposed on the base ring 140 for a
robot to transfer the substrate 101 into and out of the processing
volume 139. The substrate 101 may be placed on the substrate
support 138, which may be configured to move vertically and to
rotate about a central axis 123. A gas inlet 131 may be disposed
over the base ring 140 and connected to a gas source 135 to provide
one or more processing gases to the processing volume 139. A gas
outlet 134, formed on an opposite side of the base ring 140 from
the gas inlet 131, is adapted to an exhaust assembly 124 which is
in fluid communication with a pump system 136. The exhaust assembly
124 defines an exhaust volume 125, which is in fluid communication
with the processing volume 139 via the gas outlet 134.
[0020] In one implementation, one or more side ports 122 may be
formed over the base ring 140 between the gas inlet 131 and the gas
outlet 134. The side port 122, the gas inlet 131, and the gas
outlet 134 may be disposed at substantially the same level or
elevation. That is, the side port 122, the gas inlet 131, and the
gas outlet 134 may be intersected by a common plane. As will be
discussed in more detail below, the side ports 122 is connected to
a side gas source configured to improve gas distribution uniformity
near edge areas of the substrate 101.
[0021] FIG. 1B is a schematic cross-sectional top view of the
thermal processing chamber 100 according to one implementation of
the present disclosure. As shown in FIG. 1B, the gas inlet 131 and
gas outlet 134 are disposed on opposite sides of the processing
volume 139. Both of the gas inlet 131 and the gas outlet 134 may
have a linear or azimuthal width which approximately equals to a
diameter of the substrate support 138.
[0022] In one implementation, the gas source 135 may comprise
multiple gas sources, for example a first gas source 141, and a
second gas source 142, each configured to provide a processing gas.
During operation, processing gases from the first gas source 141
and the second gas source 142 may mix together prior to entering an
injection cartridge 149 disposed at the inlet 131. Alternatively,
the processing gas from the second gas source 142 may be introduced
to the injection cartridge 149 after the processing gas from the
first gas source 141 has been introduced to the injection cartridge
149. The first gas source 141 may provide a gas that has a lower
thermal conductivity and thus controls the combustion reaction.
[0023] In one implementation, the first gas source 141 provides an
oxygen containing gas, such as oxygen gas, and the second gas
source 142 provides a hydrogen containing gas, such as hydrogen
gas. The second gas source 142 may also provide oxygen, nitrogen,
or a mixture thereof. The gas from the first gas source 141 may be
heated to a first temperature prior to entering the injection
cartridge 149. The first temperature may be about 300.degree. C. to
about 650.degree. C., for example about 550.degree. C. The gas from
the second gas source 142 may be provided to the injection
cartridge 149 at room temperature. Alternatively, both the gas from
the first gas source 141 and the gas from the second gas source 142
may be provided to the injection cartridge 149 at room
temperature.
[0024] In one implementation, the injection cartridge 149 has an
elongated channel 150 formed therein and two inlets 143, 144 formed
on opposite ends of the elongated channel 150. A plurality of
injecting holes 151 are evenly distributed along the elongated
channel 150 and are configured to inject a main gas flow 145
towards the processing volume 139. The two-inlet design of the
cartridge 149 improves uniformity among the gas flow from each of
the plurality of injecting holes 151. The main gas flow 145 may
include 30 to 50 percent hydrogen gas by volume and 50 to 70
percent oxygen gas by volume, and have a flow rate ranging from
about 20 standard liters per minute (slm) to about 50 slm. The flow
rate is based on the substrate 101 having a 300 mm diameter, which
leads to a flow rate ranging from about 0.028 slm/cm.sup.2 to about
0.071 slm/cm.sup.2.
[0025] Under the vacuum force from the pump system 136, the main
gas flow 145 is directed from the gas inlet 131 towards the gas
outlet 134. In one implementation, the exhaust volume 125 of the
exhaust assembly 124 is configured to extend the processing volume
139 to reduce the geometry influence of the chamber structure to
the main gas flow 145. Particularly, the exhaust volume 125 is
configured to extend the processing volume 139 along the direction
of the main gas flow 145. The exhaust volume 125 may improve the
uniformity of the main gas flow 145 across the processing volume
139 from the inlet 131 to the outlet 134. The pump system 136 may
be also used to control the pressure of the processing volume 139.
In one implementation, the pressure inside the processing volume
ranges from about 1 Torr to about 19 Torr, such as between about 5
Torr to about 15 Torr.
[0026] In one implementation, a side injection assembly 147 is
coupled to the base ring 140 so that a gas is flowed along a side
gas flow 148 to the processing volume 139 via the side port 122.
The side injection assembly 147, the injection cartridge 149, and
the exhaust assembly 124 are angularly offset at about 90.degree.
with respect to each other. For example, the side injection
assembly 147 may be located on a side of the base ring 140 between
the injection cartridge 149 and the exhaust assembly 124, with the
injection cartridge 149 and the exhaust assembly 124 disposed at
opposing ends of the base ring 140. The side injection assembly
147, the injection cartridge 149, and the exhaust assembly 124 may
be intersected by a common plane. In one implementation, the side
injection assembly 147, the injection cartridge 149, and the
exhaust assembly 124 are aligned to each other and disposed at
substantially the same level.
[0027] The side injection assembly 147 is in fluid communication
with a gas source 152 via a flow adjusting device 146 configured to
control a flow rate of the side gas flow 148. The gas source 152
may include one or more gas sources. In one implementation, the gas
source 152 is a single gas source that provides a hydrogen
containing gas, such as hydrogen gas. In one implementation, the
gas source 152 is a single gas source that provides an oxygen
containing gas, such as oxygen gas. In one implementation, the gas
source 152 is a single gas source that provides a mixed gas of a
hydrogen containing gas, such as hydrogen gas, and an oxygen
containing gas, such as oxygen gas. In another implementation, the
gas source 152 is, or coupled to a remote radical source that
generate radicals to the side port 122.
[0028] In one example, the gas source 152 is a remote plasma source
(RPS) that produces hydrogen radicals to the side port 122. For a
process that heats the substrate with lamps and injects hydrogen
and oxygen into the processing chamber 100 from the slit valve 137,
the side injection assembly 147 is configured to inject the
hydrogen radicals into the processing volume 139. The hydrogen
radicals introduced from the side injection assembly 147 improve
the reaction rate along the edge of the substrate 101, leading to
an oxide layer having improved thickness uniformity. The side gas
flow 148 may have a flow rate ranging from about 5 slm to about 25
slm. For a substrate with a 300 mm diameter, the flow rate ranges
from about 0.007 slm/cm.sup.2 to about 0.035 slm/cm.sup.2.
[0029] In some alternative implementations, the gas source 152 may
contain multiple gas sources, for example a first gas source 153,
and a second gas source 154, each configured to provide a
processing gas. The first gas source 153 and the second gas source
154 may be the same or different in chemical composition. The
processing gases from the first gas source 153 and the second gas
source 154 may be mixed together prior to entering the flow
adjusting device 146. In one implementation, the side gas flow 148
may be independently controlled and may include the same gas
components as the main gas flow 145. The composition and the flow
rate of the side gas flow 148 are important factors in forming an
oxide layer having improved thickness uniformity.
[0030] In the implementation shown in FIG. 1B, the side injection
assembly 147 is a funnel-shaped structure which spreads out towards
the processing volume 139. That is, the side port 122 has an inner
diameter that increases gradually toward the substrate 101. The
side injection assembly 147 is adapted to direct the majority of
the side gas flow 148 to the edge of the substrate 101 in the shape
of a hollow cone. The edge of the substrate 101 may refer to the
peripheral region measuring from 0 mm to 15 mm, for example 10mm,
from the edge of the substrate 101. Since the funnel-shaped
structure of the side injection assembly 147 spreads out the
majority of the side gas flow 148 aiming at the edge of the
substrate 101, the gas exposure of the substrate 101 is increased
at or near the edge area. In one implementation, the inner surface
179 of the side injection assembly 147 is configured so that it
extends along a direction 189 that is substantially tangential to
the edge of the substrate 101, or substantially tangential to the
edge of the substrate supporting surface of the substrate support
138.
[0031] In addition, since the substrate 101 is rotated along
counter clockwise direction 197, the gas velocity of the majority
of the side gas flow 148 coming in from the side injection assembly
147 may be slowed down by a factor of 5 or greater, for example a
factor of 10, which results in greater growth at the edge of the
substrate 101. The gas velocity of the side gas flow 148 may be
adjusted through one or more of a flow rate of the side gas flow
148, a rotation speed of the substrate 101, and the spread out
angle of the side injection assembly 147 so that the side gas flow
148 does not travel too fast that prevents the side gas flow 148
from being adequately reacted with the main gas flow 145, or too
slow that the rotation of the substrate 101 may drag the side gas
flow 148 away from the edge of the substrate 101 without being
adequately reacted with the main gas flow 145. As a result, the
thickness profile at the edges of the substrate is improved.
[0032] The side injection assembly 147 may be made of any suitable
material such as quartz, quartz lined, ceramic, ceramic coated,
aluminum, stainless steel, steel, or the like.
[0033] Although FIG. 1B show the substrate 101 is rotating along
counter clockwise direction, the substrate 101 may be rotated along
clockwise direction and also benefit from the side gas flow
148.
[0034] To further increase the effect of the side gas flow at the
edge of the substrate 101, the side injection assembly 147 may be
configured to have one or more gas inlets pointing to the edge of
the substrate 101. FIG. 2A is a schematic cross-sectional top view
of a side injection assembly 247 having an angled gas pipe
according to one implementation of the present disclosure. The side
injection assembly 247 may be used in place of the side injection
assembly 147 shown in FIG. 1B. For sake of clarity, only the side
injection assembly 247 and the substrate 101 are illustrated.
However, it is contemplated that the side injection assembly 247
may be coupled to the base ring 140 between the gas inlet 131 and
the gas outlet 134. The side port 122, the gas inlet 131, and the
gas outlet 134 may be intersected by a common plane, as discussed
above with respect to FIG. 1B.
[0035] In the implementation of FIG. 2A, the side injection
assembly 247 is an elongated structure having a gas inlet 249
formed therein. The gas inlet 249 may be an elongated channel with
any desired shape in cross-section, such as rectangular, square,
round, polygonal, hexagonal, or any other suitable shape. The gas
inlet 249 is angled to provide a side gas flow 248 to the
processing volume 139 (FIG. 1B) via the side port 122 (FIG. 1B).
The side gas flow 248 flows along a flow path that adjusts edge
profile of the substrate 101 being processed. In one
implementation, the gas inlet 249 is configured so that gas or gas
of radicals, after existing the gas inlet 249, is flowing in a
direction that is substantially tangential to the edge of the
substrate 101, or substantially tangential to the edge of the
substrate supporting surface of the substrate support 138. It is
contemplated that the angle of the gas inlet 249 may be adjusted so
that the side gas flow 248 is flowing towards the center of the
substrate 101 (or substrate support 138), proximate the periphery
of the substrate 101 (or substrate support 138), or spatially
distributed on the substrate 101 (or substrate support 138) at any
desired location.
[0036] The side injection assembly 247 may include a single gas
inlet 249 as shown. Alternatively, the side injection assembly 247
may include a plurality of gas inlets. In such a case, the number
of the gas inlets may be about 2 inlets to about 10 inlets, which
may vary depending upon the size of the side injection assembly 247
and the size of the substrate to be processed. If multiple gas
inlets are adapted, one or more gas inlets 249 may be configured to
point upwardly towards the quartz window 114 (FIG. 1A) to limit or
prevent unwanted growth or other reactions from occurring, while
other gas inlets are pointed towards the edge of the substrate 101,
or towards the edge of the substrate supporting surface of the
substrate support 138. Alternatively, each of the plurality of gas
inlets may be pointed to the same direction.
[0037] In some implementations, the angle of the gas inlet 249 is
configured so that the side gas flow 248, either gas or gas of
radicals, is flowing in a direction that is proximate the tangent
of the substrate 101 or the substrate supporting surface of the
substrate support 138. The term "proximate" described herein refers
to a distance between the side gas flow 248 and the edge of the
substrate 101. The distance may be within about 20 mm of the edge
of the substrate 101, for example about 5 mm to about 10 mm. That
is, a flow path of the gas or gas of radicals (i.e., the side gas
flow 248) and a tangent line to the substrate 101 or the substrate
supporting surface of the substrate support 138 parallel to the
flow path of the gas or gas of radicals are about 5 mm to about 10
mm apart. Flowing of the gas or gas of radicals in a direction
proximate the tangent line of the substrate has been observed to be
able to incrementally raise the material concentration the along
the edge of the substrate 101.
[0038] Regardless of whether the side gas flow 248 (either gas or
gas of radicals) is flowed in a direction tangential to, or
proximate the edge of the substrate 101 (or the edge of the
substrate supporting surface of the substrate support 138), it has
been observed that the gas or gas of radicals significantly promote
the reaction rate along the edge of the substrate 101. For a
process that heats the substrate with lamps and injects hydrogen
and oxygen into the processing chamber 100 from the slit valve 137,
the side injection assembly 247 is configured to provide a side gas
flow 248 of hydrogen radicals. Providing hydrogen radicals at or
near the edge of the substrate 101 activates the oxygen earlier at
or near the edge of the substrate 101, leading to an oxide layer
having improved thickness uniformity along the edge of the
substrate 101.
[0039] In one exemplary implementation, the side injection assembly
247 is configured to have the gas inlet 249 pointed to the gas
injection side of the processing chamber 100, e.g., the silt valve
137. That is, the gas inlet 249 is extended along a direction
towards the gas injection side of the processing chamber. In this
way, the majority of the gas flows along the side gas flow 248
towards the gas injection side of the processing chamber 100 and
reacts with the processing gas(es) coming out of the injection
cartridge 149 (FIG. 1B) at or near the edge of the substrate 101
(or the substrate supporting surface of the substrate support
138).
[0040] FIG. 2B depicts another exemplary implementation where a
side injection assembly 257 is configured to have the gas inlet 259
pointed to the gas exhaust side of the processing chamber 100,
e.g., pump system 136. That is, the gas inlet 249 is extended along
a direction towards the gas exhaust side of the processing chamber.
In this way, the majority of the gas flows along the side gas flow
258 towards the gas exhaust side of the processing chamber 100 and
reacts with the processing gas(es) coming from the injection
cartridge 149 (FIG. 1B) at or near the edge of the substrate 101
(or the substrate supporting surface of the substrate support 138).
It has been surprisingly observed that directing gas of hydrogen
radicals towards the gas exhaust side will significantly increase
the reaction with oxygen at or near the edge of the substrate in a
process where oxygen and hydrogen are introduced into the
processing chamber from the slit valve, leading to an oxide layer
having improved thickness uniformity along the edge of the
substrate.
[0041] Similarly, the side injection assembly 247 or 257 is in
fluid communication with the gas source 152. Therefore, the side
gas flow 248, 258 may be a hydrogen containing gas, such as
hydrogen gas, or a gas of radicals, such as hydrogen radicals, as
discussed above with respect to the side injection assembly 147. In
either case, the side gas flow 248, 258 may have a flow rate
ranging from about 5 slm to about 25 slm. The flow rate is based on
the substrate 101 having a 300 mm diameter, which leads to a flow
rate ranging from about 0.007 slm/cm.sup.2 to about 0.035
slm/cm.sup.2.
[0042] The gas inlets 249, 259 may have a diameter sized to provide
the flow rate discussed above. For example, the gas inlets 249, 259
may have a diameter ranging between about 1 mm and about 2 cm, such
as between about 5 mm and about 1 cm, for example about 7 mm. The
diameter of the gas inlets 249, 259 may vary depending upon the
desired gas flow rate of the gas or gas radicals needed for the
application.
[0043] The side injection assembly 247, 257 may be made of any
suitable material such as quartz, quartz lined, ceramic, ceramic
coated, aluminum, stainless steel, steel, or the like.
[0044] Although FIGS. 2A and 2B show the substrate 101 is rotating
along counter clockwise direction, the substrate 101 may be rotated
along clockwise direction and also benefit from the side gas flow
248, 258.
[0045] FIG. 3 is a schematic cross-sectional top view of a side
injection assembly 347 having a split-type gas pipe according to
another implementation of the present disclosure. The side
injection assembly 347 has a gas pipe 369 forked into two gas
inlets 349a, 349b. The side injection assembly 347 functions
similar to the side injection assembly 247, 257 to direct majority
of gas or gas of radicals flowing along a side gas flow 348 and a
side gas flow 358 towards the gas injection side of the processing
chamber 100 (e.g., the silt valve 137) and the gas exhaust side of
the processing chamber 100 (e.g., pump system 136), respectively.
Additionally or alternatively, the gas inlets 349a and 349b may be
configured so that the side gas flow 348 and the side gas flow 358
flow in a direction that is tangential to, or in a direction
proximate the edge of the substrate 101 (or the edge of the
substrate supporting surface of the substrate support 138.
[0046] Similarly, the side gas flow 348, 358 of gas or gas of
radicals promote the reaction rate along the edge of the substrate
101. For a process that heats the substrate with lamps and injects
hydrogen and oxygen into the processing chamber 100 from the slit
valve 137, the side injection assembly 347 can be configured to
provide side gas flow 348, 358 of hydrogen radicals. Providing
hydrogen radicals at or near the edge of the substrate 101
activates the oxygen earlier at or near the edge of the substrate
101, leading to an oxide layer having improved thickness uniformity
along the edge of the substrate 101.
[0047] Even though a thermal processing chamber is discussed in
this application, implementations of the present disclosure may be
used in any processing chamber where uniform gas flow is
desired.
[0048] Benefits of the present disclosure include the use of an
improved side gas assembly in a processing chamber to direct gas or
gas of radicals towards the edge of the substrate to control growth
uniformity throughout the substrate, i.e., from the center to the
edge. The side gas assembly has an angled gas inlet configured to
point to the gas injection side (e.g., slit valve) of the
processing chamber and/or the gas exhaust side (e.g., pump system)
of the processing chamber. Particularly, it has been surprisingly
observed that directing gas of hydrogen radicals towards the gas
exhaust side, by either flowing gas of hydrogen radicals in a
directional tangential to, or proximate the edge of the substrate,
will significantly increase the reaction with oxygen at or near the
edge of the substrate in a process where oxygen and hydrogen are
introduced into the processing chamber from the slit valve, thereby
leading to an oxide layer having improved thickness uniformity
along the edge of the substrate. As a result, the overall thickness
uniformity of the substrate is improved.
[0049] While the foregoing is directed to implementations of the
present disclosure, other and further implementations of the
disclosure may be devised without departing from the basic scope
thereof, and the scope thereof is determined by the claims that
follow.
* * * * *